This is a rather loaded question, and having not had extensive experience with cordless lawn & garden tools, I’m left relying on generalities. If you’ve tried a bunch of cordless outdoor power tools, which is difficult to do since many such tools only came out in very recent years, please chime in with your experiences!
I was researching some articles you guys have regarding Dewalt and the new 40V Max Litium Ion Batteries and I thought I saw that you mentioned they will be coming out with a 20V Max version of the 6Ah battery that will power the outdoor tools like the trimmer and blower.
My first question is this, before I buy one of these tools how would it benefit me to wait for this 20V battery versus the current 40V they are including with the tool?
Next question that might be a little too techy for me to understand but I will give it a shot is in regards to the output and runtime. So basically what is the difference between a 20V battery and a 40V battery both running at 6Ah? I guess both questions are trying to achieve the same answer so any help would be appreciated so I can make an informed decision.
First, Dewalt hasn’t announced any 20V Max 6.0Ah Li-ion battery pack yet, at least not to my knowledge or active memory.
The highest capacity batteries in 20V Max and 40V Max platforms are 5.0Ah and 6.0Ah, respectively.
40V Max vs. 20V Max
Generally, the higher the voltage, the greater the power. And the greater the power, the beefier the cordless tool motor. This is with a lot of things being equal, such as considering tools of the same brand. A pro-grade 12V Max tool will often out-brute a consumer or homeowner-grade 18V or 20V Max tool.
Often, there’s a balance of greater power and runtime.
Power, in wattage, is dependent on supply voltage and current. Current draw (amps, A), not charge capacity (amp-hours, Ah), which is the spec you often see tied to cordless power tool battery packs.
Comparing the 20V Max and 40V Max blowers, note that the smaller voltage one can push air with a max speed of 90 mph, while the higher voltage one can achieve speeds of up to 120 mph. Both can push the same volume of air, which means the 40V Max blower is doing more work.
20V Max vs. 40V Max
Generally, with lower voltage tools you’ll see less power, lower costs, lower weight, smaller size, and sometimes less runtime. Often, lower voltage tools will be optimally designed for the matched battery system.
Circular saws are a great example of this. The smaller the supply voltage, the smaller the blade size, although this doesn’t necessarily hold very true anymore, thanks to the power boost made possible by brushless motors.
Which to Buy?
For larger tools, such as lawn mowers, 40V Max and even higher voltage systems are definitely the way to go. Mowers such as the Ego mower we reviewed are well-recommended with few compromises. You need that extra power in order to achieve good performance, and it’s easier to design for a higher operating voltage than to top-out the current draw of lower voltage battery packs, if even that would be enough.
For smaller tools, there’s a compromise to be made either way. Do you want a smaller and lower powered tool, or a bigger and higher powered one? The answer should depend on how you intend to use the tools.